Advocates of pasteurization make two main arguments.  First, that the process protects us against infection with harmful bacteria.  Second, that the process has minimal impact on the nutritional value of milk.

The American Medical Association, the Food and Drug Administration, the Centers for Disease Control and the American Academy of Pediatricians have released position statements endorsing the use of pasteurized milk and affirming the health risks associated with unpasteurized milk.

Anti-microbial Effects

The process of pasteurization destroys many bacteria that are harmful to humans, including:

• Staph aureus
• Campylobacter jejuni
• Salmonella
   
     
• E. coli (including O157:H7)
• Listeria monocytogenes
• M. tuberculosis
• Brucella

These organisms can be found in the intestinal lining of the animals or in their environment. 

Infection with these organisms can cause vomiting, diarrhea, renal failure, dehydration and even death.  Children, pregnant women and those with suppressed immune systems are at greater risk for severe illness.  The CDC advises the following groups to avoid unpasteurized dairy products at all times:

• Pregnant women or women considering pregnancy
• Children under 5 years of age
• The elderly
• Persons infected with HIV
• Persons with cancer
• Anyone who is immunocompromised (such as persons with organ transplants)

The CDC has reported 45 outbreaks of bacterial illness between 1998 and 2005 that were linked to the consumption of unpasteurized milk or dairy products.  These outbreaks resulted in 1007 illnesses, 104 hospitalizations and two deaths.

Nutritional Value

The FDA reports that pasteurization results in a zero- to 10 percent reduction in thiamine, folate, vitamin B12 and riboflavin, and minimally affects the casein proteins in milk.  Studies have not shown a significant difference in the nutritional content of raw versus pasteurized milk.

Effects on Enzymes and Proteins

Pasteurization does affect milk enzymes; however, the enzymes in cow’s milk are bovine enzymes and do not contribute to human metabolism of milk.  Lactose intolerance is caused by a person’s lack of enzymes to break down lactose, which is present in both raw and pasteurized milk.  Some people are allergic to milk; the proteins that they are allergic to are present in both raw and pasteurized milk.

US FDA/CFSAN - The Dangers of Raw Milk

US FDA/CFSAN - Q and A Raw Milk

US FDA/CFSAN - Food Safety and Raw Milk

CDC - Healthy Pets Healthy People